I find standing with your feet a bit further apart than maybe you do usually can make you steadier when videoing. Also slow steady breaths can help.
On trick that I used ion mydays before cameras had decent inbuilt stabilisation was to us a monopod as a balanced support. Extend the leg and support the monopod and camera just under the camera mount. Adjust the amount of extension such that if the hand is swung slightly from side to side, the camera/monopod stays vertical and doesn't pivot about your hand supporting it. A decent monopod is much cheaper and easier to carry than a tripod. It also doesn't obstruct the platform as much.
Also if you have to turn, turn with your body not your hands/arms
I might add to that, if you know that you are going to do a panned shot to follow something passing, to prevent running out of leg twist, wind yourself backwards so that the sweep is doubled. Difficult to put into words but say if you are facing the approaching train, face the track with your feet and twist yourself to start the pan and then unwind passing through neutral to twist the other way.
